MOD 2, a Bally BASIC video art program, that appeared in an article called Pix-Art by Frank Dietrich and Zsuzsanna Molnar. This article, which appeared in Computer Graphics and Art, 1980-1981 Yearbook 5, covers the Bally Arcade as a low-cost solution to create graphics using Bally BASIC and the ZGrass language. It specifically talks about several pieces of art that were written using the two languages. Some of the video art pictures are included in the article, as well as some source code for a few programs.
0:00 - MOD 2 Titles 0:08 - Overview of MOD 2 12:55 - MOD 2, Program Loads 13:18 - MOD 2 Running, Picture Drawing Begins 15:40 - MOD 2 Running, Picture 1/4 Finished 18:25 - MOD 2 Running, Picture 1/2 Finished 21:10 - MOD 2 Running, Picture 3/4 Finished 23:56 - MOD 2 Running, Picture Drawing Complete 24:10 - MOD 2 Bally BASIC Listing 24:24 - End Credits
Here are the program and its accompanying notes, as they appeared in the Pix-Art article:
Dan Sandin's program needs about 15 minutes to finish a single one of these MOD images, consisting of circles which seem to be mapped onto globes.
Some of the important aspects of this compact 10 line program are:
1. Only two nested loops create the basic structure which scans the whole screen.
2. The computation of X and Y squared for each pixel and the RM command which returns the remainder of a division, makes it possible to generate circles even in an integer basic.
3. The size of the circles depends on the value of the division factor-- D. Their growth is controlled by incrementing D after one vertical line is scanned, thus also generating the 3-D effect. Without incrementing D the result would be a regular pattern of circles of the same size.